


First Rut

by Anonymous



Category: Teen Wolf (TV)
Genre: Alpha Derek Hale, Alpha Peter Hale, Alpha/Beta/Omega Dynamics, Anal Fingering, Derek Hale in Heat, Dirty Talk, Extremely Underage, F/M, Knotting, Knotting Dildos, M/M, Mentioned parent/child incest, Multi, Omega Cora Hale, Oral Sex, Rutting, Sibling Incest, Sub Derek Hale, The Hales are one big incest family, Uncle/Nephew Incest, Uncle/Niece Incest, Vaginal Fingering
Language: English
Status: Completed
Published: 2021-03-07
Updated: 2021-03-07
Packaged: 2021-03-13 15:29:08
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Underage
Chapters: 1
Words: 3,342
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29903187
Author URL: https://archiveofourown.org/
Summary: Derek's first rut comes on while his parents and Laura are away, so it's up to his uncle and little sister to get him through it.
Relationships: Cora Hale/Derek Hale, Cora Hale/Peter Hale, Derek Hale/Peter Hale
Comments: 2
Kudos: 58
Collections: Anonymous





	First Rut

**Author's Note:**

> EXTREMELY UNDERAGE! (In case you missed the tag)
> 
> INCEST (in case you missed the tags)
> 
> READ AT YOUR OWN RISK. 
> 
> Okay, on with the show.

Derek goes into rut on a weekend when Talia, Joseph, and Laura are on a trip to look at colleges. Peter has been left to watch over Derek and Cora. 

Peter's reading a book in the library when Cora comes rushing in, pigtails flying. "Uncle Peter! Something's wrong with Derek — I think he's sick!"

Peter sighs and puts his book down, then follows Cora up the stairs to Derek's room. 

He finds him half-naked on the bed, humping a pillow. The scent of Derek's rut fils the air.

"Of course this happens when I'm in charge," Peter grumbles. 

"Is he in rut, Uncle Peter?" Cora asks, her big eyes wide and inquisitive as she looks at her brother.

Cora is an omega, but she's still too young to have had her first heat yet. She's always been precocious though, and constantly curious about how things will be once she's old enough to know.

Derek turns his head and looks at Cora, his eyes glazed over. The scent of his arousal deepens, and Peter groans.

"Absolutely not," Peter says, trying to pull Cora away. 

"He… he wants to mount me, doesn't he?" Cora asks. her voice trembles with excitement. "Oh, can I try it?"

"You are much too young for that, young lady," Peter says with a frown, though his mind is already turning. 

"I know what to do, I've seen mama and daddy and you and laura do it enough," Cora says. 

"you're too small, baby," Peter tells her. 

Derek whimpers. "Cora…"

Peter's eyes narrow. Cora moves closer to her brother, fingers twitching as if she wants to reach out. As an omega, even without being ripe, she's hardwired to want to help.

Cora looks at Peter, eyes wide and beseeching, "I can help him, can't I?"

"He can't fuck you," Peter says. "he'd hurt you."

Cora snorts. "Im a werewolf. i'd heal."

"He'd be very upset with himself when his rut was over, even if you healed."

"He can… he doesn't have to do that, does he?"

Right now, Derek just wants to get closer to Cora's scent. Peter gets an idea.

"Can you pull your dress up, Cora? See if he's satisfied with the scent of you."

Cora eagerly pulls her little sundress up, revealing her pink pony underwear. Without being asked, she wiggles out of the little panties, too. 

Derek whines and humps his pillow harder. Cora watches, seemingly enthralled. 

"What else can I do, Uncle Peter?"

Peter looks up at the ceiling, wishing his sister was here to oversee her son's first rut. When they were children, Peter and Talia's father put Peter in the cellar for his first rut, leaving him alone with no one to comfort him or help him. Talia had gone against their father's wishes and found the key to the big padlock. She'd snuck down the stairs that night and Peter had knotted his sister for the first time. Peter is reminded of that night now, and his heart goes out to Derek, who can't take his eyes off Cora.

Talia had been an alpha, and older, but she'd still taken care of her little brother in his time of need. Peter just wants to return the favor for her son.

Peter reaches out, running his hand down Derek's sweaty back. "It's okay, pup. I know you want her. I'll help, okay?"

Derek looks at him, hope in his eyes.

"Really, Uncle Peter?" Cora asks.

Peter smiles down at his niece. "Yes, but I need you to do exactly what I say, okay? He could hurt you accidentally, and we don't want that. Right, Derek?"

Derek swallows with a click. He's beyond speech at the moment, but he nods. He understands.

"Good boy," Peter says. Even though Derek is obviously an alpha, he's always shown a soft, submissive side. Peter doesn't know if Derek's even aware of it. He knows Talia has noticed, though. 

"Why don't you get up on the bed, Cora, and let Derek taste your pussy?"

Cora nods her head fast and scrambles up on the bed. She gets on her knees and spreads them, pulling her skirt up. "Like this?"

Peter smiles indulgently. "We'll try it that way at first."

Derek is shaking now, holding himself back. Peter can smell the way his arousal spikes when Cora shimmies up closer to him. He can sense Cora's excitement, too.

"Derek," Peter says sternly. "Keep your claws sheathed. Lower your head and let your sister help you."

Cora watches Derek, her eyes fascinated, as he lowers his mouth to her hairless pussy. He whines when he gets his first taste.

"Now, just as your mother taught you, Derek. I want you to please your sister. Doesn't she taste good? Almost ripe, so close to fertile. If you do your job, she'll gush all over you. you want that, don't you, boy?"

Derek whines again and nods his head, his nose bumping against Cora's clit so that she gasps. 

It's Cora's first time, and Peter wishes her mother could be here to see it. Cora's beautiful like this, flush with her first taste of sexual pleasure.

Peter takes his phone out and clicks a few pictures to share later. "Baby's first head," he murmurs to himself with amusement.

Derek's tongue is out, moving quick against Cora's pussy. Cora whines and tries to scoot closer. Derek tries to help, his hands moving under her little ass to pull her onto his mouth.

"Oh, Derek!" Cora cries out when he starts grinding his chin against her. "Uncle Peter!"

Derek growls and that's what sends Cora into orgasm, her slim body shaking uncontrollably. 

But Derek isn't satisfied. He tries to climb up off his pillow then, pulling Cora under him. His cock is heavy and hard, pointed right at Cora's soaked pussy.

"Stop," Peter growls at him. "Don't you dare."

Derek stills, but he's still intent on his little sister.

"Uncle Peter?" Cora asks shakily. 

"Don't move, sweetheart. Derek!"

Derek whines in frustration, but he knows who's in charge.

Peter realizes his nephew needs more. He's not about to let the boy knot his sister, or even fuck her. Cora is too young, too small, and even though she's an omega with instincts to help her brother through his rut, she's not ready.

"Turn around, Cora. Let your brother fuck your thighs," Peter says.

Cora turns around but looks confused. Peter moves her a little, presses her legs together. 

"Like that. See, Derek? Now you can mount her, but be careful."

Cora's pussy is dripping down her thighs anyway, and Derek's cock is wet with precome. It works out well. Peter has to stop Derek a few times when he aims a little too high, but other than that…

Derek mounts her, and he looks so big compared to her, even though he's still just fifteen. 

When Derek starts to come, Peter directs Cora to hold tighter with her legs, and then she says, "I feel it, Uncle Peter! His knot is growing!"

Derek whimpers and growls, hands clamp down on his sister's hips and he automatically stills as if he's locked inside her. 

Cora's panting now, whining a bit herself. She reaches between her legs and rubs at her swollen clit, but it's not enough for her. Smelling Derek the way she is and being so close to his knot is making her whimper and _want_ , despite the fact that she's too young for it.

"Shh, baby, you did so good," Peter tells her. Tells them both. "You're both so good."

"Please," Cora whines. Behind her, Derek is whining too, but his senses have come back a little now. 

Derek doesn't want to pull back from the hot vise of his sister's thighs, but he can't stand to see her in need, either. She did so much for him, and now she's begging for something she doesn't understand. He looks at Peter beseechingly. 

"Are you in control, Derek? Can I leave you for a moment?"

Derek nods, his eyes somewhat clear.

"Can you use words? Tell me you won't try to fuck her again."

"I won't," Derek growls, but Peter forgives him his tone. He's holding onto himself and it takes a lot. 

"Good boy. I'll be right back."

Peter rushes to the closest toy bin, which is in Laura's room. He knows Laura won't mind if this is for Cora. It takes him some time because Laura has no kind of organization in her toy chest, but then he sees what he's looking for. He finds a short, slim dildo with a bump like a little knot, something only an alpha would use — or a baby omega not yet ready for the real thing.

It's perfect for the current situation. He comes back into Derek's bedroom to find Derek flat on his back and Cora sitting on his face, grinding down on his mouth and whimpering. Both of them are facing him now, and Cora's eyes zero in on the dildo in his hands. She makes a broken sound that tells him how badly she needs it.

"Is that for me?" Cora asks breathlessly.

Peter nods. "Is Derek taking care of you?" He walks closer and sees now that Derek's knot has bulged and his cock keeps jumping, spurting little bits of come as he eats out his sister.

"Yeah, but his knot...." Cora tries to say, then moans when Derek does something particularly good.

"I know, I can see," Peter says. He looks at his nephew. "Do you think you can fuck her with this, pup? Or do I need to take care of her myself?"

Derek's eyes are glowing a soft gold. He blinks and shakes his head. He's beyond words again.

"Okay. That's good that you know your limits, baby boy. Don't worry, I'll take care of you, too."

He pulls Cora off Derek's face and they both whine. It's easier to just manhandle them both into a position he wants. He puts Cora back up to the head of the bed on her back. 

"Like that, baby. Can you hold your knees up? Let me see that pretty pussy." Then he raises an eyebrow at Derek. "Did you stretch her ass, too?"

Derek can't answer, but Cora says, "I needed it, Uncle Peter. My holes feel so empty."

"Hmm," Peter says. he holds up the dildo. "You want this in your pussy or your ass, baby?"

Cora bites her lip in indecision. 

"Can't decide?" Peter asks gently. "It's okay. We'll find a way to fill both your pretty holes."

Cora looks relieved but her body tenses in anticipation. "But what about Derek?"

"Let me worry about Derek," Peter tells her. He runs a hand over Derek's cum-soaked chest and belly, down to his cock. He wraps a hand around Derek's knot and squeezes. Not as tight as a pussy would squeeze, but enough to make his come dribble all over his belly. A tease more than anything, but really, Peter is starting to get annoyed at being the only one in charge. He doesn't mean to take it out on Derek, but Peter's always been an asshole. (A little teasing won't hurt him, after all.)

Derek whines and pushes up into Peter's hand, chasing the sensation. Peter wishes Talia was here, or even Laura. With the way Cora is right now, this rut has turned into a job for two experienced alphas.

Thankfully, Derek is easily distracted from his knot when Peter starts shallowly fucking Cora with the skinny dildo. To her, it feels like being full, and he's not sure if he needs to knot her with it or not. Maybe this will do. Derek is certainly enthralled, watching the toy disappear inside Cora's body, then practically slipping out on its way back. 

Peter's not familiar with many young omegas, but it sees Cora is producing enough slick to stay comfortable. Her ass is lubricated, too, absolutely dripping.

Peter rearranges himself on the bed so he can have both hands free. Derek moves, too, to get a better view. While one of Peter's hands uses the dildo, Peter slides the other down further so he can test the give of Cora's ass. 

It's so wet, fragrant, and incredibly needy. He sinks his thumb inside and Cora arches up and yells. "Oh, god, yes. Please, Uncle Peter, please do it some more. It feels so good."

"You close, baby girl?" Peter asks her. 

"Need more, please," Cora says. Her heart is tripping over itself it's going so fast, and the scent of omega fills the room. 

Derek growls at him and Peter fixes him with a stern look. "You've already knotted once. You're not getting more until Cora's been satisfied, understand?"

Derek flashes his eyes but sits back on his heels. 

"Now watch," Peter tells him. "Let's see what Cora likes, hmm? You never know when you'll need that information." Inwardly, he's afraid that using Cora this way might bring her heat on earlier than it would normally come. But if that's true, at least he and Derek will be familiar with her body and her needs, though they'd be amplified to new heights during her heat.

Derek breathes through his nose and grunts. Good. At least he understands.

"Please, I need more," Cora is saying, and Peter nods to himself. he pushes the dildo deeper (but not so deep the knot catches) and gives her two fingers in her ass.

Cora starts crying. Peter knows it's because she's so full of pleasure she doesn't now what to do with it. She's getting frustrated, too, though. So then Peter gently, carefully pushes the knot inside Cora's needy cunt. 

She comes beautifully, body shaking, howling cries spilling from her mouth. Peter keeps the knot inside her so she can clench down on it like a real one, so she can practice milking a cock.

He looks at Derek. "Isn't she pretty like that?"

Derek has two hands around his dick now, squeezing and tugging at himself, at his knot. There is come everywhere. 

Satisfied his nephew has himself in hand, he turns back to Cora. He gently pulls the dildo out of her and leans down to lick at her juices. He keeps two fingers in her ass because she's still coming, or maybe coming again. For her, it will all run together in a mass of pleasure, just as Peter intends.

"Good girl. That's a good girl," Peter tells her. He slowly pulls his soaked fingers out of her, then wipes them on the sheet. "Rest, now."

Cora curls up on the pillow, but she puts three of her fingers inside her pussy for comfort, to ease the emptiness. Well, that will do.

Peter turns back to Derek. "Now, what to do with you."

Derek meets his eyes and then looks over at the discarded dildo.

Peter laughs. "Oh, no. If you want a knot, you'll have to get the real thing."

Derek's pupils are so large they look blown out. He whines softly, obviously liking that idea.

"You're not a baby, Derek. If you want it, ask."

But Derek doesn't have the words. He leans over and puts his head on Peter's lap and mouths at his clothed, hard cock. Peter would have to be made of stone to not be affected by his niece and nephew's shenanigans tonight.

"I suppose that will do," Peter says as he unzips his pants and takes his hard length in hand. "Do you remember what I taught you about sucking a cock, pup?"

It's been some time since he had Derek's mouth, but the boy hasn't forgotten what to do. Even in rut — or maybe especially in rut — he's intent on bringing Peter pleasure.

Most alphas are also dominant, sometimes aggressive, and the stereotype of the big, muscled alpha topping the tiny, submissive omega is usually not far from truth. 

But Peter knows the truth about Derek, and he suspects Talia knows as well. Derek's never happier than when he gets to submit. 

As he sucks Peter's cock as if it's his favorite treat, Peter starts talking. Teasing.

"You love my cock in your mouth, don't you, baby? I bet you want me to fuck your face, make you choke on it, huh?"

Derek gives a soft whine at that.

Peter pulls out of his mouth entirely and looks over at Cora. She's sleeping, all tuckered out, and he doesn't want to disturb her rest. But Derek is moving his mouth, trying to speak.

"Shh, it's okay, pup," Peter tells him. He swings his legs over the side of bed so he's sitting, and he points to the space between his knees. "Get down on the floor, now."

Peter throws a pillow down on the carpet right before Derek moves into place. He doesn't want his nephew's knees hurting.

He smiles down at Derek and reaches out to pet his hair. "Okay. Be careful of your teeth. I'm gonna fuck your mouth just like you want, and then you're going to get up here and ride my cock like a good boy. If you're really good, I'll give you my knot. But you have to be quiet. Don't wake up your sister."

He doubts Derek understands every third word, but that's okay. He gets enough of it to whine and immediately swoop in to take Peter's cock in his sweet, giving mouth. Peter knows from experience that he likes it when Peter grabs his hair, when he makes him take it. When he thrusts into his throat and makes him cry.

When the tears are freely flowing down Derek's face, Peter pulls him up and arranges him on his lap. Of course he tests his hole first.

An alpha's hole lubricates during rut, but Derek's is wetter than most. "You're so wet for me, aren't you?" Peter teases, plunging two fingers inside Derek's hot, tight hole. "Like a perfect little bitch."

Derek whimpers and drops his head to Peter's shoulder.

"Is that right, baby boy? Are you my little bitch tonight?"

Peter tests his hole some more, gingerly adding another finger. He shouldn't have worried — Derek sucks them right in.

"Fuck, baby," Peter hisses. "You need it so bad. Your whole body is submitting to me. Like an omega slut. Do you feel empty, baby boy? Need your uncle to fill you up with a big cock?"

Derek whimpers and sucks at Peter's neck while grinding his ass against said cock.

Peter positions himself and thrusts right in, not bothering to stretch the boy any more. He's in rut, he'lll hardly remember much, and what he does remember will probably make him blush. 

Derek doesn't wait for Peter to give instructions, just starts riding Peter's cock like he was born to do it. As he bounces, his hard nipples are a perfect target to tease. Peter pinches and squeezes them, and Derek moans even louder. 

"You've even got nipples like an omega, baby bitch. You like that so much." 

Derek clenches around his cock and Peter didn't realize how close he was to coming, to knotting.

"You ready for my knot, bitch?" Peter snarls. He flashes his eyes and is gratified when Derek shows his throat in submission. Peter leans in and bites down on Derek's shoulder as he thrusts in all the way as he reaches orgasm, as his knot starts to swell.

Derek whimpers.

"Take it, just like that. You gonna come on my knot, bitch? Bet you like being stuffed full like this, feeling my knot, letting me _breed_ you."

Derek's come shoots all over Peter's chest. Peter laughs, though it's strained. He's in excruciating pleasure. Derek's so tight, like a vise around him as he continues to come.

"Good boy," Peter says, petting his hair. Derek, finally exhausted, goes limp in his arms.

* * *

"You did a good job taking care of Derek through his first rut," Talia tells him later that week.

Peter smiles. "It was my pleasure."

His sister smirks. "Knowing Derek, I'm sure it was."

**Author's Note:**

> Thank you for reading! I'm not taking prompts.


End file.
